English
E acts on N by conjugation; the action is by automorphisms of N.
Русский
E действует на N по конъюгированию; действие задаёт автоморфизмы группы N.
LaTeX
$$$\\text{conjAct} : E \\rightarrow^* \\mathrm{MulAut}(N)$$$
Lean4
/-- `E` acts on `N` by conjugation. -/
noncomputable def conjAct : E →* MulAut N
where
toFun
e :=
(MonoidHom.ofInjective S.inl_injective).trans <|
(MulAut.conjNormal e).trans (MonoidHom.ofInjective S.inl_injective).symm
map_one' := by
ext _
simp only [map_one, MulEquiv.trans_apply, MulAut.one_apply, MulEquiv.symm_apply_apply]
map_mul' _
_ := by
ext _
simp only [map_mul, MulEquiv.trans_apply, MulAut.mul_apply, MulEquiv.apply_symm_apply]